1. Field of the Invention
The present invention relates to a heat dissipation device for computer add-on cards and particularly a heat dissipation device mounted onto a graphics card for dissipating heat generated by the graphics card.
2. Description of Related Art
In order to enable desktop and other computers to rapidly process graphics and game technology, add-on units, generally referred to as “graphics cards” are often installed in computer devices. Such cards comprise a separate processor, called a GPU (graphics processor unit). When a GPU operates at high speed in a computer enclosure, its temperature is greatly increased. It is desirable to dissipate the heat quickly, for example by using a heat dissipation device attached to the GPU in the enclosure. This allows the GPU and other electronic components in the enclosure to function within their normal operating temperature ranges, thereby assuring the quality of data management, storage and transfer.
A conventional heat dissipation device comprises a heat sink and a pair of heat pipes. The heat sink comprises a base and a plurality of fins extending from the base. The base has a bottom surface attached to an electronic component and defines two grooves at a top surface opposite the bottom surface. Each heat pipe has a heat-receiving portion accommodated in one of the grooves and a pair of heat-discharging portions extending from opposite free ends of the heat-receiving portion and inserted into the top fins. The base absorbs heat produced by the electronic component and transfers the heat directly to the fins through the heat pipes. By the provision of the heat pipes heat dissipation efficiency of the heat dissipation device is improved.
However, due to structural limitations, the contact area between the heat pipes and the fins is limited, which results in the heat dissipation efficiency by the conventional heat dissipation device still cannot meet the increasing heat removal requirements of the modern heat-generating electronic devices. Furthermore, when such a conventional heat dissipation device is used to dissipate heat from the GPU of a graphics card, it cannot be equipped with an electric fan to generate an airflow forcibly expelling the heat from the fins, since a space between the graphics card a neighboring card is so limited that to install the electric fan on the fins is impracticable.